[plt-scheme] Drawing Images in Dr Scheme

From: Jens Axel Søgaard (jensaxel at soegaard.net)
Date: Sat Oct 28 20:40:06 EDT 2006

Felix Klock's PLT scheme proxy skrev:
> Joshua-
> On Oct 28, 2006, at 3:48 PM, Joshua Ewulo wrote:
>> I am currently going thru Structure and Interpretation of Computer 
>> Programs in my spare time and I need help with the section called 
>> Picture Language.
>> I can't get any of the programs in the section to work, can anyone help.
> There is a planet package that claims to provide support for the 
> Henderson picture language.
> http://planet.plt-scheme.org/#sicp.plt
> Unfortunately, it seems to be broken.  At least, it did not work "out of 
> the box" for DrScheme versions v209, v300, or v352.

Hmm. I wasn't aware that resolve-planet-path was so new.

   Welcome to DrScheme, version 352.8-svn27oct2006.
   Language: Pretty Big (includes MrEd and Advanced Student).
   > (require (lib "util.ss" "planet"))
   > resolve-planet-path

Joshua, in hend.scm simply delete these lines:

(define einstein
   (load-painter (resolve-planet-path
      '(planet "einstein.gif" ("soegaard" "sicp.plt" 1 0)))))

> According to the error messages, the package is referencing an 
> identifier, resolve-planet-path, which does not seem to be provided by 
> the modules it imports.
> I was able to at least get things working by getting rid of the 
> offending expression, which is at the definition of the einstein 
> variable.  But even then its behavior was not consistent with its 
> documentation; e.g. my attempt to use paint-hires yielded an unbound 
> identifier error.

Yes, I forgot to add it in painter.ss.

I was hoping to figure out why the operations rotate the wrong
way before updating the package. Everything seems to be defined
as in the book though - so it is hard to find.

PS: Happy birthday MF.

Jens Axel Søgaard

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